1. Field of the Invention
The present invention relates to InAlGaN (indium aluminum gallium nitride) emitting light in an ultraviolet short-wavelength region, and a process for preparing the same as well as to an ultraviolet light-emitting device using the InAlGaN emitting light in an ultraviolet short-wavelength region, and more particularly to InAlGaN emitting light in an ultraviolet short-wavelength region at room temperature with high efficiency, and a process for preparing the same as well as to an ultraviolet light-emitting device using the InAlGaN emitting light in an ultraviolet short-wavelength region at room temperature with high efficiency.
2. Description of the Related Art
Nitride semiconductors such as GaN (gallium nitride), InGaN (indium gallium nitride), and AlGaN (aluminum gallium nitride) which have been heretofore utilized as an ultraviolet light-emitting device for emitting light in an ultraviolet short-wavelength region having a wavelength of 360 nm or shorter. However, highly efficient light emission cannot be attained by such nitride semiconductors at room temperature in an ultraviolet short-wavelength having a wavelength of 360 nm or less. Accordingly, it has been concluded that an ultraviolet light-emitting device, which can emit light in an ultraviolet short-wavelength region cannot be realized by the use of such nitride semiconductors as described above.
Namely, a wavelength of up to 370 nm can be merely realized with respect to light-emitting diode as a light-emitting device wherein a nitride semiconductor is used in a short-wavelength, while only a wavelength of up to 390 nm can be realized with respect to laser diode until now.
Thus, there has been a strong need for developments as to InAlGaN exhibiting highly efficient light emission at room temperature in an ultraviolet short-wavelength region of a wavelength of 360 nm or shorter, and a process for preparing the same as well as an ultraviolet light-emitting device wherein the InAlGaN emitting light in an ultraviolet short-wavelength region is employed.